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W. S. LEVIN.

MAGNETIC FIELD CONTROLLING MEANS. APPLICATION FILED MAR. I9. 1913.

1,320,398. Patented Nov. 4, 1919.

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THE COLUMBIA PLANOORAPII C WASHINGTON, n. c.

W. S. LEVIN.

MAGNETIC FIELD CONTROLLING MEANS.

APPLICATION FILED MAR. 19.1918- Patented Nov. 4, 1919.

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UMTED STATE$ PATENT WALTER S. LEVIN, OF SAN FRANCISCO, CALIFORNIA,ASSIGNGR '10 NATIONAL SAFETY APPLIANCE COMPANY, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF CALI- FORNIA.

MAGNETIC-FIELD-CONTROLLING MEANS.

T 0 all whom it may concern:

Be it known that I, WALTER S. LEVIN, a citizen of the United States, residing at the city and county of San Francisco and State of California, have invented certain new and useful Improvements in Magnetic- Field-Controlling Means, of which the following is a specification.

The present invention relates primarily to the employment of a permanent magnet in the operation of signal, safety, or control means movable relatively thereto and preferably of a type carried by a train or other suitable movable body or object.

The principal object of the invention is to control the keeper of the permanent magnet whereby said keeper will, when the magnet is inoperative connect the pole pieces thereof to prevent the demagnetizing thereof, and when it is desired to operate the signal, safety, or control means of the body moving relatively thereto to drop said keeper, to provide a suflicient air gap between the pole pieces thereof to insure the energizing of the movable member when the same passes in close proximity to said pole pieces and through the magnetic field of said magnet.

With the above mentioned and other objects in view, the invention consists in the novel construction and combination of parts hereinafter described, illustrated in the accompanying drawings, and set forth in the claims hereto appended, it being understood that various changes in the form, proportion, size and minor details of construction within the scope of the claims may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

To more fully comprehend the invention, reference is directed to the accompanying drawings, wherein,

Figure 1 is a diagrammatic plan view of the preferred embodiment of my invention illustrating the magnet, the controlling means therefor, and the track circuit for operating said controlling means.

Fig. 2 is a plan view of the magnet in position between the track rails and with the keeper in lowered position.

Fig. 3 is a sectional view taken on line 33 of Fig. 2.

Referring more particularly to the several views of the drawings, wherein like Specification of Letters Patent.

Application filed March 19, 1918.

Patented Nov. 4, 191.9. Serial No. 223,281.

the relay 5 is an armature 6, forming a part of a motor circuit 7 within which is a source of electric energy 8. The motor circuit is adapted for the operation of a motor 9, to the armature 10 of which is connected a shaft 10, said shaft extending preferably beneath one of the rails at right angles thereto, and is mounted at its opposite end in a bearing 10 formed on a casting 11, which is positioned at one end of a suitable permanent magnet 12, formed preferably of laminations 13, said magnet being preferably of the bow or horse-shoe type. Secured to the other end of the magnet 12, is a casting 14, similar to casting 11, said respective castings retaining the pole pieces 15 which are disposed upwardly preferably at right angles to the body portion of the magnet. To the casting 14, is pivotally connected to swing on a horizontal axis through the pin 16, a keeper 17 of sufficient length to bridge the poles of the magnet, said keeper being preferably slotted as at 18 at its free end, and within said slot is positioned one end of a flexible member 19, which passes over an idler sheave 20, carried by an arm 21, on the casting 11, the opposite end of said member 19 being secured as at 22 to a winding sheave or drum 23 carried by the shaft 10. The keeper 17 operates in a suitable casing 2% which precludes dirt or other foreign material from interfering with the dropping of said keeper.

The operation of the present construction is as follows:

The shorting 'of the track circuit due to the passing of the train or car wheels 25, into the block deenergizes the track relay 5 and permits the armature 6 to drop, at which time the weight of the keeper 17 unwinds the flexible member 19 from the drum Cir arn'iature permitting the free end of the keeper 1? to drop sui'liciently within the casing 2% to provide an air gap of sufficient distance between the free end thereof and its cooperating pole piece. \Vith the keeper in this position a movable member passing over the pole pieces 15, and within the magnetic field of the magnet will be energized sufficiently thereby to ope ate the signal, safety, or controlling means connected therewith. On the passing of the wheels from the block the track relay will be energized through the source of electric energy in the track circuit and will raise the armature 6 completing the motor circuit, at which time the motor will be operated to wind the flexible connection 19 onto the sheave and raise the keeper so that the same will connect the ends of said magnet.

While we have illustrated the keeper as being electrically operated, it is to be understood that the same may be operated by any other suitable form of mechanism if desired, just so long as the said keeper is moved from the magnet to insure the said magnet energizing a suitable electric element when the same is moved within the field thereof, and to thereafter cause a movement of said keeper to connect the poles of said magnet to insure the permanency thereof,

Having thus described my invention what I claim is 1. In combination with a magnet of the horseshoe type, a keeper cooperating with the poles thereof for bridging the same, and means for moving said keeper to provide an air gap between the same and its cooperating pole of a distance not less than the distance between the said poles.

2. In combination with a magnet of the horseshoe type, a keeper cooperating with the poles thereof for bridging the same, and means for moving said keeper to disconnect the same from one of said poles to provide between the end thereof and said pole from which it is disconnected an air gap of a width not less than the distancebe-tween said magnet poles.

3. In combination with a magnet, a keeper coiiperating with the poles thereof for bridging the same, and electrically controlled means for operating said keeper to move the same to and from one of said magnet poles.

at. In combination with a magnet of the horseshoe type, a keeper cooperating with the poles thereof for bridging the same and pivotally supported at one pole, and means cooperating with the free end of said keeper for permitting movement of the same rela tively to the other pole.

5. In comblnation with a magnet meniber of the shore-shoe type and a keeper member for bridging the poles thereof, one of said members movable relatively to the other, and means for moving said movable member to the other member to bridge the poles of the magnet and whereby said movable member is permitted to move by gravity from the other member to provide an air gap between the poles of said magnet.

6. In combination with a magnet of the horse-shoe type, a keeper pivotally mounted to one of the poles of said magnet to swing on a horizontal axis and adapted to contact with the other pole to bridge the same, means for raising the free end of said keeper to maintain the same longitudinally disposed in contact with its cooperating pole, said means capable of releasing to permit the lowering of the free end of said magnet to provide an air gap between the free end thereof and its cooperating pole.

7. In combination with a magnet of the horse-sho type, a keeper pivotally mounted at one end to one of the poles of said magnet to swing on a horizontal aXis and adapt ed to contact with the other pole to bridge said poles, and means for moving the free end of said keeper relatively to its cooperating pole whereby said poles may be either bridged or separated by an air. gap between the free end of said keeper and its cooperating pole.

8. In combination with a magnet of the horse-shoe type, a keeper pivotally mounted at one end to one of said magnet poles to swing on a horizontal axis, and adapted to contact with the other pole to bridge said poles, a flexible connection attached at one side to the free end of said keeper, a sheave to which the other end of said connection is secured, said sheave capable of rotating in one direction for raising the free end of said keeper to bridge said magnet poles and capable of operating in another direction due to the weight of said keeper to provide an air gap between the free end of the said keeper and its cooperating pole.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WALTER 5. LEVIN.

Witnesses:

HARRY A. TOTTEN, D. B. RICHARDS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. G. 

